I submitted pset1 and there is some feedback in the gradebook, but how do I know if I passed the assignment? What's my grade?
Its name is grader, but this does not mean that it will assign you with grades like A, B, C ... The grader's feedback will be there in the CS50 Gradebook after a certain time. The feedback is in the range of 0 to 1. 1 represents all correct answers and 0 represents all wrong answers, and intermediate values point towards partially corrected answers. 0.6 (i.e. 60%) is the threshold value for each pset to earn a certificate.
Have a look at curiouskiwi's answer, its in a bit more detail.